Conventionally, with respect to a target workpiece recognized by a three-dimensional vision sensor, a robot control apparatus connected to a robot and the three-dimensional vision sensor moves the robot from an upward-position above a pick-up position to a position where the target workpiece is detected, and picks up the target workpiece by using a hand attached to an end of an arm of the robot. In this case, the robot control apparatus performs the operation of picking up the target workpiece by moving the arm so as to move the hand from the upward-position to the position where the target workpiece is recognized and detected by the three-dimensional vision sensor.
When the hand is moved in a linear manner from the upward-position to the position where the target workpiece is recognized and detected by the three-dimensional vision sensor, there is a possibility that the move is interfered with by a surrounding environment (such as peripheral jigs and a box in which the target workpiece is placed). In this case, it is necessary to calculate a non-interference area with avoiding the interference area to move the hand from the upward-position to the position where the target workpiece is detected.
Since various cases are supposed as the surrounding environment where the robot is placed, it is necessary in each case to generate a specific program (a control procedure using a language created for managing conditions of the robot move) appropriate to the surrounding environment, in order to calculate the non-interference area with avoiding the interference area to move the hand. Furthermore, if the surrounding environment has a complicated shape or if the surrounding environment is changed or added during a process, it causes a troublesome task to modify the program.
Patent Literature 1 discloses a technique that divides a space adjacent to a grasp target into space cones each having a predetermined size and a vertex at a grasp position, selects an open space cone that does not interfere with a surrounding object from the space cones, calculates a distance from the surrounding object to the selected open space cone, and determines a grasp attitude based on the distance.